Prostatitis is a common disease affecting 2%-10% of men at some point in their lives. Acute bacterial prostatitis, chronic bacterial prostatitis, or asymptomatic inflammatory prostatitis is diagnosed in 5%-10% of prostatitis cases, while chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) accounts for the remaining 90-95% of cases. Chronic prostatitis/chronic pelvic pain syndrome can be further characterized as inflammatory (Category IIIA) or non-inflammatory (Category IIIB) depending on whether leukocytes are present or absent, respectively, in prostatic fluid. The etiologies of categories IIIA or IIIB prostatitis are not completely known. The absence of culturable microorganisms in prostatic secretions of category IIIA and IIIB patients suggests that the disease is not due to an infectious agent;however, studies have shown that bacterial 16S ribosomal DNA (rDNA) was found at a high frequency in prostatic or periprostatic tissue from men with CP/CPPS. There was also a high correlation between the presence of 16S rDNA and inflammatory cells in prostatic secretions. These two results indicate that cryptic, extremely fastidious, or unculturable bacteria may be involved in CP/CPPS. It is also conceivable that intracellular bacteria, which would not be present is prostatic secretions, may provide a reservoir of infection and source of chronic inflammation. A large number of studies have shown that E. coli are capable of invading bladder epithelial cells and establishing intracellular colonies that can cause recurrent urinary tract infections. We have developed a method to assess the ability of E. coli to invade prostate epithelial cells in vitro and observe differences in the invasiveness of E. coli strains. Cellular invasion is also dependent on factors present in normal serum. The first specific aim of research proposed here is to elucidate the E. coli virulence factors in E. coli prostatitis isolates required for invasion. The second specific aim is to define inflammatory mediators released by epithelial cells after E. coli invasion. Results from these studies will test the hypothesis that invasion of prostate epithelial cells and subsequent release of inflammatory mediators may be the basis for CP/CPPS. PUBLIC HEALTH RELEVANCE: Chronic prostatitis/chronic pelvic pain syndrome is the most common form of prostatitis and causes significant patient morbidity. While the etiology of the disease is unknown, there is evidence of cryptic bacteria in patient's prostate tissue, which may be a source of ongoing infection and inflammation. The objectives of the research proposed are thus to elucidate virulence factors E. coli strains that can invade prostate epithelial cells and to identify inflammatory mediators released by cells after invasion.